The need for a sturdy and easily manipulated ladder shelf attachment is evident in view of the many prior patents on the subject, mostly by individual inventors. Yet it is equally evident that none have met with much commercial success. Aside from cost, some factors contributing to this lack of commercial success include non-adaptability to different types and styles of ladders, and non-ergonomic designs that are awkward to transport, deploy and store. In other words, what is needed is a removable ladder shelf apparatus that is: (1) easily stored and transported; (2) easily installed on a deployed ladder (preferably with one hand, so that the user can maintain three support points during installation and removal of the apparatus); and (3) adapted to be used with different types and styles of ladders, including both straight ladders and stepladders, and ladders having various types and styles of rungs or steps.